Herbicides and fungicides play a significant role in ensuring that an adequate food supply at reasonable prices reaches the ever-increasing world population. The high-yield cultivation of rice is essential to ensure an adequate food supply in many countries. Itinerant weeds and grasses in the presence of rice, also a grass, dramatically reduce crop yield. Consequently, considerable research s being conducted to control, if not eliminate, such undesirable weeds and grasses. Herbicides and fungicides useful in the cultivation of rice must have selective biological activity wherein the unWanted grasses and weeds are caused to wither and die while leaving the rice unharmed by the treatment.
Certain chloroacetanilides have been identified as herbicides for the pre-emergent treatment and control of weeds and grasses in rice crops. Representative chloroacetanilides are disclosed in U.S. Pat. No. 4,322,553 which relates to a process for preparing N-(halomethyl)acrylamides as represented by the formula: ##STR3## wherein X includes hydrogen, the halogens, a C.sub.1 -C.sub.6 alkyl or haloalkyl radical, a C.sub.3 -C.sub.7 cycloalkyl radical, a phenyl or benzyl radical; R includes a C.sub.1-20 alkyl radical and a phenyl radical, and R.sup.2 is a chloro or bromo atom.
U.S. Pat. No. 4,028,093 teaches meta-bis-anilide derivatives which demonstrate utility as herbicides. The bis-anilide derivatives are represented by the formula: ##STR4## in which R.sub.1 and R.sub.2 are independently selected from hydrogen alkyl, alkoxyalkyl, cycloalkyl, pinonyl, ethylcycloalkyl, lower alkenyl, halogenated lower alkyl, benzyl, ethylphenyl, 2,4-dichlorophenoxymethylene, styryl, furyl, phenyl or substituted phenyl in which the substituents are nitro, halogen, methyl or methoxy; R.sub.3 and R.sub.4 are independently selected from hydrogen, or lower alkyl; X and Y are independently selected from oxygen or sulfur; and Z s a halogen, nitro, amino, lower alkyl, lower alkoxy or trifluoromethyl and n is an integer having a value from 0 to 4. The compounds are stated to be effective herbicides for controlling grasses and broadleaf plants demonstrating both pre-emergent and post-emergent activity.
U.S. Pat. No. 4,324,580 teaches 2,6-diethyl-N-(1'-methoxyprop-2'-yl)-[N]-chloroacetanilide as a plant growth regulating and herbicidal agent having improved stability in the soil.